The invention concerns a method for rescuing a person sifting in an ejection seat that has ejected from an aircraft in an emergency, wherein depending on data collected by measuring apparatus arranged on the ejection seat a control device initiates deployment of stabilizing and/or braking parachutes attached to the seat and furthermore initiates separation of the person from the ejection seat.
In terms of ejection seats in prior art, deployment of stabilizing and/or braking parachutes as well as separation of the person sitting in the ejection seat are controlled by mechanical machines, like barometrically controlled clocks, in that after the ejection seat has separated from the aircraft the rescue sequence is carried out in successive stages with deployment of stabilizing parachutes and/or braking parachutes and or seat/person separation after pre-established periods of time and depending on the measured barometric air pressure as a measure of the current altitude of the ejection seat.
This type of process is associated with the disadvantage that the deployment of the stabilizing and/or braking parachutes and the separation of the person from the ejection seat transpires without factoring in the current actual flight movement of the ejection seat, since the only variables available are the time elapsed since the ejection seat separated from the aircraft and the change in air pressure. This means that for initiating and coordinating the rescue sequence no consideration is given to whether the aircraft at the time the ejection seat deployed was located, e.g., in a mountainous region at a relatively low altitude above the ground or whether the ejection seat, e.g., deployed toward the ground while the aircraft was in an inverted flight attitude; in either of the latter situations initiation of the different stages of the rescue sequence based solely on the time and/or barometric control can lead to incorrect actuation times that are associated with a corresponding high risk to the person in the ejection seat. Furthermore, it is disadvantageous that the current speed of the ejection seat is not factored into the initiation of deployment of the appropriate parachutes so that in some cases the parachutes open, e.g., too early with a concomitant risk of damage or even that they open too late, which jeopardizes the success of rescue measures.
A further development of such an ejection seat encompasses equipping it with a dynamic airspeed indicator by means of which the change in dynamic pressure can be used to make judgments about negative acceleration, i.e., the delay in the movement of the ejection seat, so that predetermined times can be assigned for triggering initiation of the individual stages of the rescue sequence. Set in the control device that controls the rescue sequence are three time levels to be initiated that are based on the combination of high altitude/low speed, low altitude/high speed, and the aircraft on the ground (no altitude/no speed). For each alternative a window of time is established for initiating the rescue sequence so that again there is no adaptation to the current movement of the ejection seat in space.
Known ejection seats and their resultant rescue sequences are thus generally associated with the disadvantage that measurements are not taken until the ejection seat has deployed from the aircraft (and thus the control of the rescue sequence, however simple, does not begin until then); for instance, the period of time from ejection to the first possible deployment of a stabilizing and/or braking parachute is at least two seconds so that crucial time has passed before it is possible to initiate rescue measures--time that the person sitting in the ejection seat does not have, particularly in unfavorable ejection conditions.
The object of the invention is therefore to improve a method of the type specified in the foregoing such that the rescue sequence is better adapted to the actual flight and the danger to the person sitting in the ejection seat is reduced.